1999 "EE" Evinrude 70HP 4-Stroke Service Manual, P/N 787023, Page 178Get this manual
Description of Operation DR7557
Trim-OutTilt-Up
1When the UP button is pressed, the motor and gear pump will rotate in clockwise direction
2Pressurized oil will open UP check valve and the oil will flow through UP shuttle valve to the DOWN shuttle valve Following operation of valveDOWN check valve will open mechanicallythereby pushing the trim and tilt pistons upward
ITJ 3Pressurized oil flows through the UP check valve to the bottom of the trim and tilt cylinders,
4Residual oil in the upper area of the tilt cylinder is returned to the pump through DOWN check valve 5Any oil in the area above both trim cylinder pistons will be returned to the reservoir6Oil will then flow from the reservoir to the pump to stabilize the balance of the oil volumes